Computing systems typically possess input devices such as a mouse, trackball, or other pointing device to permit a user to provide input commands. These commands may include a set of commands to alter an image being viewed by the user upon a display device. Various mechanisms may be employed to define a command that alters the image being displayed.
Any of these mechanisms typically would instruct the computing system to scroll an image in either the vertical or horizontal direction or to zoom an image in and out. Typically, a separate mechanism is used to alter the scroll position of the image in each dimension. The zoom operation, that moves an image inward and outward as the image is enlarged and reduced, is similar to a scroll operation in a dimension perpendicular to the screen of the viewing device. These mechanisms typically require a user to manipulate a control object on the screen of the viewing device that is translated into a command to alter the image being displayed. These mechanisms also require a user to manipulate the pointing device to provide the commands needed to manipulate the screen control object.
For hand-held devices, the use of a separate pointing device requires a user to both hold the viewing device as well as manipulate the pointing device to provide the needed commands. Such an operation may prove to be difficult. In many cases, the image being displayed for viewing on the screen of the viewing device represents a small portion of a larger document, such as a portion of a large map being displayed. The user simply desires to navigate around the larger image, at various levels of zoom, to discover information of interest. Especially for a hand-held device, this operation is similar to moving a paper map around a center of a field of view relative to a user. At present, a computing device has not been instructed to manipulate an image being displayed to a user with the use of this simple and intuitive interface.
By determining the proximity of a user to viewing device, and by determining changes in the proximity information, the image being displayed to the user may be altered using the simple yet intuitive interface that is similar to the manner in which users interact with ordinary objects on a daily basis. By integrating such a feature into viewing devices, the user interface of the computing system may be improved. No such user interface has existed in computing systems to date. A system consistent with the invention disclosed herein addresses these deficiencies of prior computing systems.